Tool holder, in particular a fast exchange chuck

Abstract

A tool holder, particularly a fast exchange chuck preferably for thread cutting, thread shaping and the like has a receptacle having one end receivable in a machine spindle, a machine tool receptacle and the like, and another opposite end provided with a head having a coaxial cylindrical head opening, a housing received and guided in the cylindrical head opening non-rotatably but displaceably in a longitudinal direction and provided with a coaxial cylindrical housing opening, a fast exchange insert insertable in the housing opening a torque-transmitting unit for transmitting torque between the head and the housing and including a head longitudinal groove provided in the head, a housing longitudinal groove provided in the housing, and at least one drive body partially received in each of the longitudinal grooves so as to transmit torque between the head and the housing and to roll during a relative displacement between said head and said housing. The at least one drive body is arranged between said head and said housing guidance-free with respect to its position in a longitudinal direction and is acted upon from outside inwardly with a pressing force, and an elastic clamping member applies the pressing force from outside inwardly to the drive member.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims: 
     
       1. A tool holder, particularly a fast exchange chuck preferably for thread cutting, thread shaping, or the like, comprising a receptacle having one end receivable in a machine spindle, a machine tool receptacle, or the like, and another opposite end provided with a head having a coaxial cylindrical head opening; a housing received and guided in said cylindrical head opening non-rotatably but displaceably in a longitudinal direction and provided with a coaxial cylindrical housing opening; a fast exchange insert insertable in the housing opening; torque-transmitting means for transmitting torque between said head and said housing and including a head longitudinal groove provided in said head, a housing longitudinal groove provided in said housing, and at least one drive body partially received in each of said longitudinal grooves so as to transmit torque between said head and said housing and to roll during a relative displacement between said head and said housing, said at least one drive body being arranged between said head and said housing guidance-free with respect to its position in a longitudinal direction and being acted upon from outside inwardly with a pressing force; and an elastic clamping member applying the pressing force from outside inwardly to said drive member. 
     
     
       2. A tool holder as defined in claim 1, wherein said head has a cylinder wall, said head longitudinal groove being formed as a longitudinal slot which is throughgoing in a transverse direction and provided inside said cylinder wall. 
     
     
       3. A tool holder as defined in claim 2, wherein said at least one drive body engages in a transverse direction through said longitudinal slot and projects at least insignificantly over an outer side of said head in the region of said longitudinal slot. 
     
     
       4. A tool holder as defined in claim 1, wherein said elastic clamping member is formed as a circumferential clamping member which at least partially surrounds said head over its outer side in the region of said at least one drive body and engages a projecting part of said at least one drive body from outside. 
     
     
       5. A tool holder as defined in claim 4, wherein said circumferential clamping member is formed as an elastically springy ring-shaped element of metal. 
     
     
       6. A tool holder as defined in claim 5, wherein said ring-shaped element is formed as a ring. 
     
     
       7. A tool holder as defined in claim 5, wherein said ring-shaped element is formed as a cylinder sleeve. 
     
     
       8. A tool holder as defined in claim 4, wherein said circumferential clamping member is fixed on said head in an axial longitudinal direction. 
     
     
       9. A tool holder as defined in claim 4, wherein said circumferential clamping member is interrupted in a longitudinal direction in at least one point. 
     
     
       10. A tool holder as defined in claim 1, wherein said housing is provided with a plurality of said housing longitudinal grooves, at least one of said housing longitudinal grooves having a trapezoidal cross-section which is symmetrical and has a line of symmetry extending in a diametrical plane through a center of said housing. 
     
     
       11. A tool holder as defined in claim 1, wherein said head has a plurality of said head longitudinal grooves, at least one of said head longitudinal grooves being formed as a longitudinal slot which has two opposite and substantially parallel flanks, each extending in a plane of a secant at a radial distance from a center of said housing and parallel to a diametrical plane extending through said center of said housing. 
     
     
       12. A tool holder as defined in claim 1, wherein said at least one drive body is formed as a drive ball. 
     
     
       13. A tool holder as defined in claim 11, wherein said at least one drive body is formed as a drive ball, said flanks of said longitudinal slot being spaced from one another by a distance substantially corresponding to a diameter of said drive ball. 
     
     
       14. A tool holder as defined in claim 11, wherein said at least one drive body is formed as a drive ball, said flanks of said longitudinal slot being spaced from one another by a distance which is at least insignificantly greater than said diameter of said drive ball. 
     
     
       15. A tool holder as defined in claim 1, wherein said head has four said head longitudinal grooves and said housing has four said housing longitudinal grooves so as to form four cooperating longitudinal groove pairs, said torque transmitting means including four said drive bodies each located in a respective one of said longitudinal groove pairs. 
     
     
       16. A tool holder as defined in claim 15, wherein first two of said longitudinal groove pairs are located in a first circumferential region, while second two of said longitudinal groove pairs are located at a second circumferential region which is offset relative to said first circumferential region by a circumferential angular distance of substantially 60° and so that between two neighboring ones of said longitudinal groove pairs a circumferential region of substantially 120° which does not have any grooves is provided. 
     
     
       17. A tool holder as defined in claim 15, wherein each of said longitudinal groove pairs is located diametrically opposite to another one of said longitudinal groove pairs in a diametrical plane so that all said longitudinal groove pairs are located opposite to each other in two diametrical planes, said two diametrical planes extending relative to one another at an angle of substantially 60° and a complementary angle of substantially 120°. 
     
     
       18. A tool holder as defined in claim 1; and further comprising an axial longitudinal compensating device for pulling and pressing and operating simultaneously as a bevel pressure amplifier, said device being arranged on an outer side of said head and on an outer side of said clamping member. 
     
     
       19. A tool holder as defined in claim 18, wherein said clamping member is formed as a circumferential clamping member, said circumferential clamping member has an outer side provided with a ring groove, said longitudinal compensating device including a plurality of balls having a circumferential part located in said ring groove, a supporting ring having one side provided with an inclined surface and surrounding said circumferential clamping member, and a spring pressing said supporting member so that said inclined surface abuts in an axial longitudinal direction against a projecting circumferential part of said balls. 
     
     
       20. A tool holder as defined in claim 19, wherein said spring is formed as a pressure spring. 
     
     
       21. A tool holder as defined in claim 19; and further comprising an outer sleeve which surrounds said housing and is fixedly connected with the latter, said outer sleeve having a cylindrical neck which limits a ring chamber with said head and said outer side of said circumferential clamping member, said longitudinal compensating device being arranged in said ring chamber. 
     
     
       22. A tool holder as defined in claim 21; and further comprising a ball holder abutting against said outer sleeve in an axial direction and arranged in said ring chamber, said ball holder having openings in which said balls are held, said supporting ring being arranged on an associated end of said ball holder and contacting with said inclined surface said balls which at least insignificantly project at said end. 
     
     
       23. A tool holder as defined in claim 1; and further comprising a central inner pipe for a cooling medium supply, said pipe having an end mounted on said receptacle and extending from said end into said head and into said head opening and also in a central opening of said housing, said tube containing an inner ring chamber provided for a cooling medium and sealed at both its axial ends, said ring chamber communicating with an interior of said tube through at least one channel and also communicating with a plurality of channels provided in said housing outside its center and leading to said housing opening. 
     
     
       24. A tool holder as defined in claim 23; and further comprising a substantially cup-shaped closure member which is mounted on said housing and forms an additional chamber, said tube having a free end which is closed and extends through a central axial opening in said housing and into said additional chamber. 
     
     
       25. A tool holder as defined in claim 23; and further comprising a blocking ring which is axially displaceably arranged in said housing opening and surrounds said closure member, said blocking ring being sealed in a a circumferential direction relative to said housing. 
     
     
       26. A tool holder as defined in claim 25, wherein said closure member has an axial end provided with at least one radially extending projection, said blocking ring having an end provided with at least one radially inwardly extending projection which abuts against said radially extending projection of said closure member when said blocking ring is displaced by a spring force. 
     
     
       27. A tool holder as defined in claim 26, wherein said radially extending projection of said closure member is formed with a ring shoulder, said radially inwardly extending abutment of said blocking ring being formed as an abutment shoulder. 
     
     
       28. A tool holder as defined in claim 24, wherein said blocking ring has an end provided with at least one transverse passage, said housing having a substantially axis-parallel passage with which said at least one transverse passage communicates, said closure member and said blocking ring forming therebetween a ring chamber at a circumferential side with which said transverse passage is connected. 
     
     
       29. A tool holder as defined in claim 28, wherein said transverse passage is formed as a transverse groove. 
     
     
       30. A tool holder as defined in claim 29, wherein said closure member has a free end provided with at least one recess which communicates with said ring chamber within said closure member and said blocking ring for supplying the cooling medium. 
     
     
       31. A tool holder as defined in claim 24, wherein said wherein said chamber of said closure member in which said free end of said tube extends is ventilated toward outside. 
     
     
       32. A tool holder as defined in claim 31, wherein said housing has a ventilating opening, said pipe having an opening through which said chamber of said closure member communicates with said ventilating passage. 
     
     
       33. A tool holder as defined in claim 31, wherein said housing has a ventilating opening, said pipe having an opening through which said chamber of said closure member communicates with said ventilating passage, said closure member and the free end of said tube extending in said closure member having a ring chamber therebetween through which said chamber of said closure member communicates with said ventilating passage.